Cavity substrate having directional optoelectronic transmission channel and manufacturing method thereof

ABSTRACT

A cavity substrate may have a directional optoelectronic transmission channel. The cavity substrate includes a support frame, a first dielectric layer on a first surface of the support frame, and a second dielectric layer on a second surface of the support frame. The support frame, the first dielectric layer and the second dielectric layer constitute a closed cavity having an opening on one side in the length direction of the substrate, a first circuit layer is arranged on the inner surface of the first dielectric layer facing the cavity, an electrode connected with an optical communication device is arranged on the first circuit layer, the electrode is electrically conducted with the first circuit layer, a second circuit layer is arranged on the outer surfaces of the first dielectric layer and the second dielectric layer, and the first circuit layer and the second circuit layer are communicated through a via column.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 USC § 119(a) of ChinesePatent Application No. 202010912209.0, filed on Sep. 2, 2020, in theChina Intellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND 1. Technical Field

The invention relates to an electronic device packaging structure, inparticular to a cavity substrate with a directional optoelectronictransmission channel and a manufacturing method thereof.

2. Background of the Invention

Optical fiber technology has become more and more popular, andoptoelectronic modules have been widely used. The current optoelectronicmodule is mainly composed of a receiving optical subassembly, atransmitting optical subassembly, an optical interface, an internalcircuit board, a heat conducting frame, a shell, and like portions. Onthe transmit side of the optoelectronic transceiver, a laser diode andassociated circuits are used to generate a modulated optical signal(representing data) that is ultimately coupled into an output signalpath (optical fiber, waveguide, etc.); the receiving optical subassemblyis to assemble a light receiving device on the receiving side PCB. Thelight receiving device is generally integrated inside one metal tubeshell by a photodetector (APD tube or PIN tube), preamplifier andthermistor, and like component parts. One or more input optical signalsare converted from an optical signal to an electrical signal within aphotodiode or similar apparatus. Because the electrical signal is veryweak, amplification apparatuses (e.g., transimpedance amplifiers) aregenerally used to enhance signal strength before attempting to recoverdata information from the received signal.

As the demand for optical transceiver modules continues to increase,individual unit assembly methods become problematic such that thereremains a need for different methods of optical transceiver assemblythat can improve the efficiency of the construction process whilemaintaining the integrity of the module (including the precise opticalalignment between the required components).

In order to complete the manufacturing of the optoelectronictransceiving integrated module structure, the traditional manufacturingprocess needs one-stage and one-stage assembly, the whole process ismultiple in procedures, the production efficiency is low, the externalforce resistance of the assembled optoelectronic transceiving integratedmodule structure is poor, and the tightness of the assembledoptoelectronic transceiving integrated module structure is not goodenough, making it easy to suffer from water vapor erosion.

CN107422429B discloses a system-in-package structure integratingoptoelectronic transceiving function and a manufacturing method thereof,wherein a sending module and a receiving module of an optoelectronicmodule and a control circuit of the optoelectronic module are integratedinto one system-in-package through a special metal shell part and asystem-in-package (SIP) process. However, the structure can only attachthe optoelectronic device and the passive device on the surface of thesubstrate, the packaging area and the volume are large, and therequirement of miniaturization cannot be met; in addition, the lightemitting device and the light receiving device need to be separated by ametal blocking wall in the packaging procedure so as to prevent theinterference between signals, thereby increasing the manufacturing stepsand increasing the packaging volume.

SUMMARY

The implementation of the present invention is directed to providing acavity substrate having a directional optoelectronic transmissionchannel and a manufacturing method thereof, so as to solve theabove-mentioned technical problem. According to the invention, a cavityfor installing the optical communication device is arranged in thepackaging substrate such that the problem of surface mounting of theoptical communication device is solved, and the packaged volume can beremarkably reduced compared with the prior art; the positions of thelight receiving device and the light emitting device are separated suchthat the interference of optical signal is avoided, and the noise pointof a signal is reduced; no metal blocking wall needs to be added,process steps are reduced, and the manufacturing cost is reduced.

The first aspect of the present invention relates to a cavity substratehaving a directional optoelectronic transmission channel, the cavitysubstrate comprising a support frame, a first dielectric layer locatedon the first surface of the support frame, and a second dielectric layerlocated on a second surface of the support frame. The support frame, thefirst dielectric layer and the second dielectric layer constitute aclosed cavity having an opening on one side in a length direction of thesubstrate, a first circuit layer is arranged on an inner surface of thefirst dielectric layer facing the cavity, at least one electrodeconnected with an optical communication device is arranged on the firstcircuit layer, the electrode is electrically conducted with the firstcircuit layer, a second circuit layer is arranged on outer surfaces ofthe first dielectric layer and the second dielectric layer, and thefirst circuit layer and the second circuit layer are communicatedthrough a via column.

In some embodiments, the optical communication device comprises a lightemitting device or a light receiving device such that an open side ofthe cavity forms a directional optoelectronic transmission channel ofthe optical communication device.

In some embodiments, when the optical communication device is placed inthe cavity, the electrode is connected with a terminal of the opticalcommunication device, and an optical communication active surface of theoptical communication device faces the open side of the cavity.

In some embodiments, the support frame comprises an insulating layer;preferably, the insulating layer comprises polyimide, epoxy resin,bismaleimide/triazine resin, polyphenyl ether, polyacrylate, prepreg,film-like organic resin, or a combination thereof.

In some embodiments, the first dielectric layer and the seconddielectric layer comprise a thermosetting dielectric material;preferably, the first dielectric layer and the second dielectric layercomprise a thermosetting dielectric material containing glass fiber asthe reinforcing material. The materials of the first dielectric layerand the second dielectric layer may be the same or different.

In another aspect of the present invention, there is provided amanufacturing method for a cavity substrate having a directionaloptoelectronic transmission channel, comprising the following steps:

(a) preparing a support frame, wherein the support frame comprises aninsulating layer, a via column penetrating through the insulating layerin a thickness direction and a cavity surrounded by the insulatinglayer;

(b) applying an adhesive layer on a first surface of the support frame,and mounting an active metal block on the adhesive layer exposed in thecavity, wherein the active metal block comprises an electrode coatedwith etching-resistant metal at a bottom of the active metal block;

(c) laminating a second dielectric layer on a second surface of thesupport frame to fill a gap of the cavity;

(d) removing the adhesive layer;

(e) forming a first circuit layer on the first surface of the supportframe, and connecting the electrode to the first circuit layer;

(f) laminating a first dielectric layer on the first circuit layer;

(g) forming a second circuit layer on outer surfaces of the firstdielectric layer and the second dielectric layer;

(h) removing dielectric in the cavity to expose the active metal block;

(i) etching the active metal block and the etching-resistant metalcoating the electrode; and

(j) cutting along a scribe line of the support frame to obtain thecavity substrate having a directional optoelectronic transmissionchannel.

Preferably, the adhesive layer in step (b) comprises a tape.

Preferably, the active metal block in step (b) is a copper block or analuminum block.

Preferably, the etching-resistant metal coated on the electrode isselected from at least one of nickel or titanium.

In some embodiments, the first dielectric layer and the seconddielectric layer comprise a thermosetting dielectric material;preferably, the first dielectric layer and the second dielectric layercomprise a thermosetting dielectric material containing glass fiber asthe reinforcing material.

In some implementations, step (e) comprises the following substeps:

(e1) sputtering a first metal seed layer on the first surface of thesupport frame;

(e2) applying an adhesive first photoresist layer on the surface of thefirst metal seed layer;

(e3) patterning the first photoresist layer to form a circuit pattern;

(e4) depositing copper in the circuit pattern to form the first circuitlayer such that the electrode is connected with the first circuit layer;

(e5) applying a second photoresist layer on the first circuit layer;

(e6) patterning the second photoresist layer to form a first conductivehole;

(e7) depositing copper in the first conductive hole to form a firstconductive column; and

(e8) removing the first photoresist layer and the second photoresistlayer, and etching away the first metal seed layer.

Preferably, the copper is deposited by electroplating.

In some embodiments, step (f) comprises laminating the first dielectriclayer on the first circuit layer and the first conductive column, andthinning and flattening the first dielectric layer by means of nog plateor plasma etching to expose the end of the first conductive column.

In some implementations, step (g) comprises the following substeps:

forming a second conductive hole in the second dielectric layer;

sputtering a second metal seed layer on the first dielectric layer andthe second dielectric layer;

electroplating copper on the second metal seed layer to form a copperlayer;

applying a third photoresist layer on the copper layer;

patterning the third photoresist layer to form a circuit pattern;

etching the copper layer and the second metal seed layer to form thesecond circuit layer; and

removing the third photoresist layer.

Preferably, a second conductive hole is formed in the second dielectriclayer through laser trepanning.

Preferably, step (h) comprises opening the cavity by a laser process andremoving the dielectric in the cavity to expose the active metal block.

Preferably, step (i) comprises introducing an etching liquid into thecavity through an opening opened by a laser to etch the active metalblock and the etching-resistant metal coating the electrode.

Preferably, the scribe line comprises a centerline of the cavity suchthat a cavity opening is formed in a side edge of the substrate aftercutting.

Preferably, after forming the cavity substrate unit, installing anoptical communication device in the cavity and/or surface mounting theoptical communication device on the second circuit layer may becomprised.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show theimplementation thereof, reference is now made, purely by way of example,to the accompanying drawings.

When referring to the accompanying drawings, it must be emphasized thatthe specific illustrations are exemplary and only for the purpose ofdemonstrative discussion of the preferred embodiments of the presentinvention, and are presented based on the provision that they areconsidered to be the most useful and understandable illustration of thedescription of the principles and concepts of the present invention. Inthis regard, no attempt is made to show structural details of theinvention in more detail than is necessary for a fundamentalunderstanding of the invention; the description with reference to thedrawings will enable one skilled in the art to recognize how the severalforms of the invention may be embodied in practice. In the drawings:

FIG. 1 is a schematic cross-sectional view of a cavity substrate havinga directional optoelectronic transmission channel according to oneembodiment of the present invention;

FIGS. 2A-2K show schematic cross-sectional views of intermediatestructures at each step of the manufacturing method of the cavitysubstrate shown in FIG. 1 .

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring to FIG. 1 , there is shown a schematic cross-sectional view ofa cavity substrate 100 having a directional optoelectronic transmissionchannel. The cavity substrate 100 includes a support frame 101, a firstdielectric layer 102 on the lower surface of the support frame 101, anda second dielectric layer 103 on the upper surface of the support frame101. The support frame 101 and the first dielectric layer 102 and thesecond dielectric layer 103 constitutes a closed cavity 104 with anopening on one side in the length direction of the substrate 100, afirst circuit layer 1021 is arranged on the inner surface of the firstdielectric layer 102 facing the cavity 104, at least one electrode 105connected with an optical communication device is arranged on the firstcircuit layer 1021, and the electrode 105 and the first circuit layer1021 are electrically conducted. A second circuit layer 1022 is arrangedon the outer surfaces of the first dielectric layer 102 and the seconddielectric layer 103, and the first circuit layer 1021 and the secondcircuit layer 1022 communicate through a via column 1011. A plurality ofvia columns 1011 may be arranged within the support frame 101 as TOchannels, which may be the same or different in size. The via column1011 is generally a copper via column.

The cavity 104 is substantially enclosed by the frame 101 and the firstdielectric layer 102 and the second dielectric layer 103, but is open onone side in the length direction, i.e., the open side is on the side ofthe cavity substrate 100. An optical communication device may bearranged within the cavity 104 such that the open side of the cavity 104forms a directional optoelectronic transmission channel for the opticalcommunication device.

When the optical communication device is installed in the cavity 104,the electrode 105 arranged in the cavity 104 is connected with theterminal of the optical communication device, and the opticalcommunication acting surface of the optical communication device facesthe open side of the cavity 104. The optical communication devicecomprises a light emitting device or a light receiving device, and themounting mode can be changed according to actual requirements. Forexample, the light receiving device may be placed within the cavity 104and the light emitting device is mounted on the surface of the cavitysubstrate 100. Therefore, not only can the volume of the packaging bodybe remarkably reduced, but also the light receiving device and the lightemitting device are thus separately arranged. The light paths of thelight receiving device and the light emitting device are respectively inthe length direction and the thickness direction of the substrate suchthat without adding a metal blocking wall the interference of an opticalsignal can be avoided, and the noise point of the signal, the processprocedures, and the manufacturing cost can be reduced.

The support frame 101 includes an insulating layer and a metal viacolumn extending through the insulating layer. Preferably, theinsulating layer may comprise polyimide, epoxy, bismaleimide/triazineresin (BT), polyphenyl ether, polyacrylate, prepreg (PP), film-likeorganic resin (ABF), or a combination thereof, such as a combination ofPP and ABF.

The first dielectric layer 102 and the second dielectric layer 103 mayinclude a thermosetting dielectric material or a photosensitive resinmaterial, preferably a thermosetting dielectric material containingglass fiber as a reinforcing material to secure the strength of thecavity substrate 100. The first dielectric layer 102 and the seconddielectric layer 103 may comprise the same material or may comprisedifferent materials.

As shown in FIG. 1 , a first solder resist layer 106 and a second solderresist layer 107 may also be formed outside the first dielectric layer102 and the second dielectric layer. A conductive column 1023 may alsobe formed in the first dielectric layer 102 to communicate the secondcircuit layer 1022 and the first circuit layer 1021.

Referring to FIGS. 2A-21 , there is shown a schematic cross-sectionalview of intermediate structures of each step of the manufacturing methodof the cavity substrate 100 having a directional optoelectronictransmission channel of FIG. 1 .

The manufacturing method of the cavity substrate 100 with thedirectional optoelectronic transmission channel comprises the followingsteps: preparing a support frame 101-step (a), as shown in FIG. 2A. Thesupport frame 101 includes an insulating layer 1012, a via column 1011extending through the insulating layer, and a cavity 104 located in theinsulating layer, with a cutting line 1013 arranged in the middle of thecavity 104.

In general, the manufacturing method of the support frame 101 includesthe following substeps:

obtaining a sacrificial carrier;

applying a copper seed layer on the sacrificial carrier;

applying a corrosion-resistant layer on the copper seed layer;

applying another copper seed layer on the corrosion-resistant layer;

applying a photoresist layer;

the patterned photoresist layer having a copper via pattern;

plating copper into the pattern to form a via column 1011;

stripping the photoresist layer;

laminating an upstanding copper column (and optionally copper via) witha polymer dielectric to form an insulating layer 1012;

thinning and flattening to expose the end of the copper column (and thecopper via);

applying a corrosion-resistant material;

removing the carrier and the copper column;

removing the blocking layer; and

removing the etching protection layer to form the cavity 104.

Next, an adhesive layer 110 is applied to the lower surface 101 a of thesupport frame 101, and an active metal block 111 is mounted on theexposed adhesive layer 110-step (b), as shown in FIG. 2B. The bottomsurface of the active metal block 111 is disposed with an electrode 105coated with an etching-resistant metal. The adhesive layer may be atape, generally a commercially available transparent film that isthermally decomposable or decomposable under ultraviolet radiation. Theactive metal block 111 is arranged within the cavity 104 and mounted onthe exposed adhesive layer 110. The active metal block 111 is a metalthat is very susceptible to corrosion by corrosive liquids, generally acopper block or an aluminum block. The electrode 105 is constituted ofmetallic copper, the surface of which is generally coated with anetching-resistant metal that is at least one of nickel or titanium.Generally, the etching-resistant metal needs to be removed with aspecific corrosive liquid that is different from the corrosive liquidthat etches the active metal block 111.

Then, the second dielectric layer 103 is laminated on the upper surface101 b of the support frame 101 such that the gap of the cavity 104 isfilled with the dielectric-step (c), as shown in FIG. 2C. After theactive metal block 111 is fixed, the second dielectric layer 103 islaminated on the upper surface 101 b of the support frame 101 such thatit fills the cavity 104 to further fix the active metal block 111.Generally, the second dielectric layer material is a thermosettingdielectric material, preferably a thermosetting dielectric materialcontaining glass fiber as the reinforcing material, to form a strongsecond dielectric layer 103 to secure the strength of the cavitysubstrate 100.

Next, the adhesive layer 110 is removed-step (d), as shown in FIG. 2D.The adhesive layer 110 may be removed by direct peeling or by heat orlight.

Then, the first circuit layer 1021 is formed on the lower surface 101 aof the support frame 101, the electrode 105 is connected with the firstcircuit layer 1021, and then the conductive column 1023 is prepared onthe first circuit layer 1021-step (e), as shown in FIG. 2E. Generally,the following substeps are included:

(e1) sputtering a first metal seed layer on the lower surface 101 a ofthe support frame 101;

(e2) applying a first photoresist layer on the first metal seed layer;

(e3) patterning the first photoresist layer to form a circuit pattern;

(e4) depositing copper in the circuit pattern to form the first circuitlayer 1021 such that the electrode 105 is connected with the firstcircuit layer 1021;

(e5) applying a second photoresist layer on the first circuit layer1021;

(e6) patterning the second photoresist layer to form a first conductivehole;

(e7) depositing copper in the first conductive hole to form the firstconductive column 1023; and

(e8) removing the first photoresist layer and the second photoresistlayer, and etching away the first metal seed layer.

Generally, the first metal seed layer may be formed on the lower surface101 a of the support frame 101 by sputtering a metal such as copper,titanium, etc. The first photoresist layer and the second photoresistlayer may be photosensitive dry films. The first circuit layer 1021 maybe formed by depositing copper within the circuit pattern byelectroplating metallic copper such that the electrode 105 is connectedwith the first circuit layer 1021. The terminal of the opticalcommunication device may be connected with the first circuit layer 1021through the electrode 105 and fanned out through the via column 1011.The first conductive hole can be formed in the second photoresist layerin a mechanical trepanning mode, a photoetching trepanning mode or alaser trepanning mode; the first conductive column 1023, which may be asolid copper column or hollow copper column plated with copper at theedges, is then formed by depositing copper in the first conductive holeby electroplating metallic copper.

Next, the first dielectric layer 102 is laminated on the first circuitlayer 1021 and the first conductive column 1023-step (f), as shown inFIG. 2F. The first dielectric layer 102 may then be thinned andflattened by nog plate or plasma etching to expose the end of the firstconductive column 1023. Generally, the first dielectric layer 102comprises a thermosetting dielectric material, preferably athermosetting dielectric material containing glass fiber as thereinforcing material, to form a strong first dielectric layer 102,thereby ensuring the strength of the cavity substrate 100.

Then, the second circuit layer 1022 is formed on the outer surfaces ofthe first dielectric layer 102 and the second dielectric layer 103-step(g), as shown in FIG. 2G. Generally, the following substeps areincluded:

carrying out trepanning in the second dielectric layer 103 to form asecond conductive hole;

sputtering a second metal seed layer on the first dielectric layer 102and the second dielectric layer 103;

electroplating copper on the second metal seed layer to form a copperlayer;

applying a third photoresist layer on the copper layer;

patterning the third photoresist layer to form a circuit pattern;

etching the copper layer and the second metal seed layer to form thesecond circuit layer 1022; and

removing the third photoresist layer.

Generally, the second conductive hole may be formed in the seconddielectric layer 103 by means of a mechanical trepanning, aphotolithographic trepanning or a laser trepanning, and the second metalseed layer may be formed by sputtering metals such as copper, titanium,etc. The first circuit layer 1021 and the second circuit layer 1022 arecommunicated through the via column 1011.

Then, the first solder resist layer 106 and the second solder resistlayer 107 are formed on the second circuit layer 1022 on the uppersurface and lower surface of the substrate 100, respectively-step (h),as shown in FIG. 2H. After forming the first solder resist layer 106 andthe second solder resist layer 107, a bonding pad is formed on theexposed metal surface of the second circuit layer 1022, and the bondingpad may be subjected to a metal surface treatment such as theapplication of green oil or the like.

Then, the dielectric in the cavity 104 is removed to expose the activemetal block 111; the active metal block 111 and the etch-resistant metalcoating the electrode 105 are etched-step (i), as shown in FIG. 2I.Generally, the dielectric within the cavity 104 may be ablativelyremoved by a laser process to expose the active metal block 111. Thecorrosive liquid may be introduced into the cavity 104 through anopening formed by a laser process to corrode the active metal block 111,and then a specific etching liquid is introduced to remove theetch-resistant metal coating the electrode 105, thereby exposing theelectrode 105.

Finally, the cutting is performed along the cutting line 1013 of thecavity 104 to obtain a cavity substrate 100 unit having a directionaloptoelectronic transmission channel-step (j), as shown in FIG. 2J. Thecutting may be performed along the cutting line 1013 using a rotatingsaw web or other cutting technique such as a laser, resulting in thecavity substrate unit 100.

FIG. 2K shows one cavity substrate unit 100 obtained after cutting.

In a practical application of the cavity substrate unit 100, an opticalcommunication device may be installed in the cavity 104 such that theterminal of the optical communication device is connected with theelectrode 105 and is fanned out to be connected with the second circuitlayer 1022 through the first circuit layer 1021 and the via column 1011and the first conductive column 1023. The surface mounting of theoptical communication device may also be performed on the second circuitlayer 1022 such that the cavity substrate 100 has an opticalcommunication device with different optical path directions. Anoptical-path-coupled light emitting and light receiving circuit can beformed by combining a plurality of cavity substrates 100 on which anoptical communication devices is installed. Therefore, since the opticalcommunication device does not need to be completely surface-mounted, thevolume of the packaging body can be remarkably reduced, the lightreceiving device and the light emitting device are thus separatelyarranged, and respective optical paths are respectively in the lengthdirection and the thickness direction of the substrate such that theinterference of optical signal can be avoided, and noise point of thesignal can be reduced; therefore, a metal blocking wall does not need tobe added, the process steps can be reduced, and the manufacturing costcan be reduced.

Those skilled in the art will recognize that the invention is notlimited to what has been particularly shown and described hereinaboveand hereinafter. Furthermore, the scope of the invention is defined bythe appended claims, including combinations and sub-combinations of thevarious technical features described hereinabove, as well as variationsand modifications thereof, which would occur to persons skilled in theart upon reading the foregoing description.

In the claims, the term “comprising” and variations thereof such as“comprises”, “comprise”, and the like, mean that the recited assembly isincluded, but generally other assemblies are not excluded.

What is claimed is:
 1. A method for manufacturing a cavity substratehaving a directional optoelectronic transmission channel, the methodcomprising: (a) preparing a support frame, wherein the support framecomprises an insulating layer, a via column penetrating through theinsulating layer in a thickness direction, and a cavity surrounded bythe insulating layer; (b) applying an adhesive layer on a first surfaceof the support frame, and mounting an active metal block on the adhesivelayer exposed in the cavity, wherein the active metal block comprises anelectrode coated with etching-resistant metal at a bottom of the activemetal block; (c) laminating a second dielectric layer on a secondsurface of the support frame to fill a gap of the cavity; (d) removingthe adhesive layer; (e) forming a first circuit layer on the firstsurface of the support frame, and connecting the electrode to the firstcircuit layer; (f) laminating a first dielectric layer on the firstcircuit layer; (g) forming a second circuit layer on outer surfaces ofthe first dielectric layer and the second dielectric layer; (h) removingdielectric in the cavity to expose the active metal block; (i) etchingthe active metal block and an etching-resistant metal coating theelectrode; and (j) cutting along a scribe line of the support frame toobtain the cavity substrate having a directional optoelectronictransmission channel.
 2. The manufacturing method for a cavity substratehaving a directional optoelectronic transmission channel according toclaim 1, wherein the adhesive layer in step (b) comprises a tape.
 3. Themanufacturing method for a cavity substrate having a directionaloptoelectronic transmission channel according to claim 1, wherein theactive metal block in step (b) is a copper block or an aluminum block.4. The manufacturing method for a cavity substrate having a directionaloptoelectronic transmission channel according to claim 1, wherein theetching-resistant metal coated on the electrode is selected from atleast one of nickel or titanium.
 5. The manufacturing method for acavity substrate having a directional optoelectronic transmissionchannel according to claim 1, wherein the first dielectric layer and thesecond dielectric layer comprise a thermosetting dielectric material. 6.The manufacturing method for a cavity substrate having a directionaloptoelectronic transmission channel according to claim 5, wherein thefirst dielectric layer and the second dielectric layer comprise athermosetting dielectric material containing glass fiber as areinforcing material.
 7. The manufacturing method for a cavity substratehaving a directional optoelectronic transmission channel according toclaim 1, wherein step (e) comprises the following substeps: (e1)sputtering a first metal seed layer on the first surface of the supportframe; (e2) applying an adhesive first photoresist layer on the surfaceof the first metal seed layer; (e3) patterning the first photoresistlayer to form a circuit pattern; (e4) depositing copper in the circuitpattern to form the first circuit layer such that the electrode isconnected with the first circuit layer; (e5) applying a secondphotoresist layer on the first circuit layer; (e6) patterning the secondphotoresist layer to form a first conductive hole; (e7) depositingcopper in the first conductive hole to form a first conductive column;and (e8) removing the first photoresist layer and the second photoresistlayer, and etching away the first metal seed layer.
 8. The manufacturingmethod for a cavity substrate having a directional optoelectronictransmission channel according to claim 7, wherein the copper isdeposited by electroplating.
 9. The manufacturing method for a cavitysubstrate having a directional optoelectronic transmission channelaccording to claim 1, wherein step (f) comprises laminating the firstdielectric layer on the first circuit layer and the first conductivecolumn, and thinning and flattening the first dielectric layer by meansof nog plate or plasma etching to expose the end of the first conductivecolumn.
 10. The manufacturing method for a cavity substrate having adirectional optoelectronic transmission channel according to claim 1,wherein step (g) comprises the following substeps: forming a secondconductive hole in the second dielectric layer; sputtering a secondmetal seed layer on the first dielectric layer and the second dielectriclayer; electroplating copper on the second metal seed layer to form acopper layer; applying a third photoresist layer on the copper layer;patterning the third photoresist layer to form a circuit pattern;etching the copper layer and the second metal seed layer to form thesecond circuit layer; and removing the third photoresist layer.
 11. Themanufacturing method for a cavity substrate having a directionaloptoelectronic transmission channel according to claim 1, wherein step(h) comprises opening the cavity by a laser process and removing thedielectric in the cavity to expose the active metal block.
 12. Themanufacturing method for a cavity substrate having a directionaloptoelectronic transmission channel according to claim 11, wherein step(i) comprises introducing an etching liquid into the cavity through anopening opened by a laser to etch the active metal block and theetching-resistant metal coating the electrode.
 13. The manufacturingmethod for a cavity substrate having a directional optoelectronictransmission channel according to claim 1, wherein the scribe linecomprises a centerline of the cavity such that a cavity opening isformed in a side edge of the substrate after cutting.